Project : alcove
Design of surgical simulators
We have designed a generic framework, called MISS, for the design of surgical simulators. It mainly relies on SPORE, and provides some usefull tools to ease the implementation of minimally invasive surgical simulation. It defines classes for the cinematic of a trocart-like insertion tools, proposes the simulation of various tools such as forceps, coagulator... and includes various visual effects (smoke, coagulation,...).
Spic is the first application of the MISS framework. It allows the simulation of coelioscopy and laparoscopy. It provides a virtual camera for the environment simulation and two inserted tools which the user can choose and change during simulation. A specific device has been designed to provide an adequate user interface, but, for cost reason, do not include any force feedback. Instead, we use a real shell which prevents the forceps from penetrating through the virtual cavity. This implies a good calibration of the manipulator, which is hopefully possible .
However, since the organs are mobile, we have to find another way to interact properly with them. We have chosen the previously described proxy/god-object method to allow the virtual forceps and the organ to behave realistically, even if the surgeons imposes impossible position to the forceps. This work is currently under progress. We are also concerned with the simulation of realistic operations: This implies to design specific models: we have already proposed a model for the fallopian tubes and go on with the modeling of the ovaries, uterus and peritoneum.
We are also involved in the pedagogy associated with such simulators. A user-friendly interface has been designed by Cédric Tailly to propose simple exercices to learn anatomic recognition and the handling of the camera and forceps. More realistic exercices are currently being investigated, and the use of specific tools is now possible (evacuator, coagulator, water injector, cutting forceps,...).
Cataract Surgery Simulation
The cataract operation consists in extracting the opaque cristalline lens from the eye and replace it by an implant. This project lies within the framework of Minimal Invasive Surgical Simulator (MISS), which aim is to create pedagogical simulators for doctors.
To do so, we develop both physical and virtual interfaces. The physical interface is based on the phantom and forces feedback. The virtual interface uses different mechanical models implemented in the SPORE physical engine, such as 2D and 3D objects for cutting. Other effects are managed in a pure geometrical maner.
Six people have worked on this simulator, most of all during a trainee period. This simulator allow us to enrich the SPORE project 4.1, particularly with new mechanical models. The first one is surfacic mass/spring mesh with the ability to be torn or cut (F. Blondel , D. Marchal and C. Syllebranque); it is used to simulate the capsulorhexis stage. The second one is articulated rigid body (M. De La Gorce); we plan to model the lens implant. Finally, D. Marchal worked on a volumetric mass/spring mesh in order to simulate the eye lens to be destroyed. Moreover, V. Pegoraro have added the stereographic display of any scene and C. Syllebranque  has designed a visual effect connected to the mechanical model to simulate the hydrodissection stage. By now, F. Blondel is putting the finishing touches to an operational caspulorhexis stage simulation. To produce a realistic gesture, the design of a physic tool (based on a Phantom device and a model of the eye), and its calibration with the virtual tools, are also in progress.